The invention generally relates to a latchplate, or tongue assembly or tongue as they are also called, which is part of a seat belt safety restraint system, and more particularly to a tongue whose operation is changeable from a cinching mode of operation in which the seat belt is cinched or clamped between two relatively moveable walls to a slip mode of operation in which the seat belt is loosely received within a determinable sized opening within the tongue and during which the seat belt is generally free to slide through the opening.
Reference is briefly made to FIG. 1 which is illustrative of a typical three-point seat belt system 20. The system includes an anchor 22 coupled to a seat belt buckle 24. The buckle includes an opening to receive a tongue 30 and a latching mechanism that is typically received within a corresponding opening of the tongue. The system 20 includes a length of seat belt 32 which is arranged to define a shoulder belt portion 34 and a lap belt portion 36. The lap belt portion 36 is typically anchored to the floor by an anchor 38. The shoulder belt portion extends over a D-ring or web guide 40 and is rewound under the operation of a seat belt retractor 42. As is known in the art, the anchor 38 can be replaced by a second retractor. FIG. 1 illustrates the buckled condition of the system 20 in which the tongue 30 is received within the seat belt buckle 24. The tongue 30 will typically define the demarcation between the shoulder belt portion and the lap belt portion of the seat belt 32. When the user releases the tongue 30 from the buckle 24, the retractor 42 (or retractors) rewinds the seat belt on a spool which is part of the retractor. In this stored, rewound condition, the shoulder belt 32 will be oriented in a generally vertical configuration as also shown in FIG. 1 with the tongue 30 positioned at some location on the vertically positioned, stored seat belt webbing 32.
Safety restraint systems utilize a number of different of types of tongues. One tongue is permanently secured to the seat belt 32 at corresponding ends of the shoulder belt portion 34 and seat belt portion 36. Another type of tongue is called a "slip tongue" and includes a narrow slot through which the seat belt is received. As can be appreciated, if the lap belt portion 36 is placed under load, the shoulder belt portion 32 will slip through the tongue opening permitting the lap belt portion to enlarge. The same is true upon loading only the shoulder belt portion, that is, the lap belt portion 36 will slide upwardly through the tongue opening, permitting the length of the shoulder belt portion to increase (provided the seat belt retractor is locked). Depending upon the relative size of the seat belt slot within the tongue, the slip tongue can also be referred to as a free-falling tongue, that is, when the seat belt is retracted to its stored vertical position, the tongue 30 is permitted to fall downwardly under the influence of gravity to a fixed position. This fixed position is defined by the retractor or alternatively by a button, of known variety, which is secured to a portion of the seat belt.
Another type of tongue is referred to as a "cinching or clamping tongue." As an example, with the seat belt secured about the occupant, generally in the configuration as illustrated FIG. 1, and with loads applied to either the shoulder belt portion 34 or the lap belt portion 36, this type of tongue includes a moveable bar or slide which pinches, cinches or clamps the seat belt 32 against a cooperating surface of the tongue or latchplate. As can be appreciated, in this type of tongue, once the cinching mode of operation is activated, the transfer of the seat belt 32 between the shoulder belt portion 34 and the lap belt portion 36 is prohibited (below a definable level of applied belt force). Obviously, if the various dimensions of the internal parts of the tongue are chosen correctly, this type of cinching or clamping tongue can also operate as a free-falling tongue, after the webbing has been moved to its stored condition.
With certain types of vehicles riding over typically rough roads, the cinching type of tongue can provide for some minor discomfort to the wearer. As an example, as a stiffly sprung vehicle, such as a truck or other off-the-road vehicle rides over an extremely bumpy road, the occupant is prone to bouncing upon the seat cushion 46. A small amount of slack will be created in the seat belt 32 about the occupant's lap as the occupant bounces downwardly and compresses the cushion 46. This slack is quickly reduced by the operation of the rewind spring of the retractor 42. When the occupant returns to his or her normally seated position, the occupant will experience that the seat belt 32 has become more tightly secured about his or her body. As the vehicle progresses over the bumpy road, the seat belt will become even more tightly enveloped about the occupant, which as mentioned above, may lead to some minor discomfort.
The present invention is directed to a cinching or clamping tongue which can also operate as a slip tongue upon the activation of a manually adjustable knob or button.
Accordingly the invention comprises: a tongue having multiple modes of operation comprising: a frame, a slide (or clamp) and manually adjustable knob or button. The tongue frame includes a locking feature for locking engagement with a seat belt buckle, a seat belt receiving first aperture positioned apart from the locking feature; the first aperture including a first belt clamping surface. The slide or clamp includes a second belt clamping surface generally opposite the first belt engaging surface, the slide being arranged to slide upon the frame in the vicinity of the first aperture from a belt release position which the seat belt is freely sliding to a belt clamping or cinching position in which the seat belt is clamped or cinched between the first and second belt clamping surfaces, the slide further includes a first belt engaging surface arranged to urge the slide toward its clamped position. The knob or locking means is mounted upon the frame and operable to block the motion of the slide, and rotatable from an unlocked position to a locked position, wherein when in the unlocked position the slide is permitted to slide to its cinching position and when in the locked position the slide means is maintained in the release position.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.